The present invention relates to medical devices for hemostasis, and methods of using the medical devices for hemostasis. More particularly, the present invention relates to medical devices for effecting hemostasis at a puncture wound with an indwelling tubular element extending therethrough.
Puncture of blood vessels is a necessary stage in many of the minimally invasive approaches to diagnosis and treatment, including interventional radiology and cardiology. Therefore, a need to create hemostasis as rapidly as possible following the procedure becomes an important priority.
Various hemostatic agents, such as synthetic or natural cationic polymers, hydrogels, collagen based products, oxidized cellulose, gelatin derivatives, topical thrombin, astringents, vasoconstrictors, etc. have been and are being utilized. Most conventional devices and methods of application are designed as a pad or dressing, incorporating these hemostatic agents to the bleeding site, puncture site or wound site.
Certain medical procedures require insertion of a tubular element, such as catheter, introducer or tube in an artery or other vessel of a patient. The insertion of such tubular element makes it difficult to provide an effective hemostasis at a puncture wound because the hemostatic substances can not be applied directly and intimately under pressure to the bleeding or wound site. Also, an immediate hemostasis is often needed during surgery while a tubular element is still in the vessels of the patient or after the tubular element is removed. Therefore, what is needed is a simple, safe and effective device and method for providing more directly and intimately hemostasis to the bleeding site with an indwelling tubular element, such as catheter, introducer or tube, and allowing the tubular element to be easily removed thereafter.
The present invention provides a device and method for effecting hemostasis at a wound site with an indwelling tubular element, such as catheter, introducer or tube disposed therein.
Many hemostasis methods have been utilized or attempted, including suture-based devices, collagen plugs, pressure applying devices, and the like. The situation is complicated further by the use of anticoagulants in these procedures, which prolongs clotting times. Substances such as heparin, aspirin, coumadin, and other anticoagulants are used with regularity and affect the normal blood coagulation cascade. The use of cationic substances in flocculation and coagulation in non-medical situations such as water treatment, paper production, industrial sludge treatment, and the like has been effectively used in the past and is well documented. The method of action is by precipitating, coagulating or flocculating suspended particles which are negatively charged by virtue of using positively charged materials, which attract the oppositely charged ions.
It has been clearly demonstrated that the charge on blood cells and components (platelets, etc.) is negative. By using a positively charged biocompatible substance, it is possible to agglomerate these cells creating coagulation through a system other than by virtue of the normal clotting cascade. Innocuous polymers are positively charged (cationic substances) as the initiator of coagulation in clinical situations. Additionally, positive charges can be applied via iontophoretic methods using electrode pads and positively charged treatment sites to accomplish the same thing.
The use of a positive charge administered by either cationic substances or by iontophoretic means to quickly create a coagulation process and hemostasis until the normal clotting cascade can take over. This can occur even in the face of significant anticoagulation since the process is ionic and not effected by the anticoagulants, which operate on the normal blood cascade. This approach can be revolutionary in the after treatment of patients with minimally invasive or invasive procedures since rapid hemostasis and mobilization of the patient are desirable endpoints.
The cationic substance can be incorporated into many forms, such as woven and non-woven pads, fibers, gels, pastes, waxes, foams, sprays, liquids of varying viscosities, packings, membranes, sheets, and the like. Additionally, these forms can be incorporated and utilized with iontophoretic types of equipment that create a positive charge at the bleeding site to effect coagulation.
Utilizing colloidal chemistry for effecting coagulation ionically in suspensions or colloidal substance by providing cationic charges, has enormous value in the diagnosis and treatment of conditions such as cardiovascular disease, interventional radiological procedures, and the like. The cationic charge can be provided by a substance with a positively charged surface, or electronically by utilizing electrophoretic type equipment and electrode pads specifically designed to be disposable, conductive and sterile, designed to fit the required anatomical site. Many cationic substances are available, such as polymers, polysaccharides and starches, aluminum salts, magnesium salts, natural polymers such as chitosan, and the like.
The use of ionic charges to create hemostasis is a new and important process in the treatment of disease processes. This novel approach can be administered by applying sterile, biocompatible, positively charged materials directly in contact with the blood column, accompanied by pressure, or provided electronically by utilizing controlled direct current on the positive side with iontophoretic type approaches and specially constructed, disposable, sterile electrodes to the bleeding site
According to one aspect of the present invention, a hemostatic pad defines an opening at a proximally central point of the pad. The opening is sized to allow egress of the indwelling tubular element through the pad. The pad further comprises an application surface, which contains hemostatic agent used for effecting hemostasis at the wound site associated with an indwelling tubular element. The hemostatic agent preferably is a cationic substance, such as cationic polymer, or a cationic protein. The hemostatic substance on the pad, therefore, may be applied evenly, directly and intimately around the tubular element, also providing an even application of pressure for hemostasis. It also allows the indwelling tubular element to be easily removed from the wound site through the pad. In a preferred embodiment, the opening of the pad is a slit extending from an approximate center to an edge of the pad. In another preferred embodiment, the opening is constructed as an aperture with a slit extending from the aperture to an edge of the pad.
According to another aspect of the present invention, the hemostatic pad may have a non-slip etched area on a top surface of the pad, in order to achieve more friction between the finger of a surgeon and the surface of the pad. The non-slip etched area make it easier to apply a pressure to a puncture site, and make the hemostasis more efficiently and quickly.
According to another aspect of the present invention, the hemostatic device comprises an adhesive bandage which preferably has a xe2x80x9cBand Aid(trademark)xe2x80x9d-like shape. The adhesive bandage includes a non-adhesive central portion and an adhesive peripheral portion, preferably two adhesive ends, extending from two opposite side of the non-adhesive central portion. The adhesive bandage defines an aperture at an approximately central point of the central portion and an elongated cut extending from the aperture to an edge of the non-adhesive central portion. The aperture is sized to allow passage of the tubular element, for example, catheter or introducer. The bandage may further include two peelable films covering the two adhesive ends of the bandage. A hemostatic effective amount of hemostatic agent or a hemostatic pad with the hemostatic agent attached thereon is attached to the non-adhesive central portion for effecting a hemostasis at a puncture wound where the adhesive bandage is applied.
According to another embodiment of the present invention, the hemostatic device includes an adhesive bandage and a hemostatic pad attached to a bottom surface of the adhesive bandage. The bandage includes an adhesive backing, an absorbent layer or pad attached to a bottom surface of the backing, and a flexible disc attached to a top surface of the backing. The adhesive backing includes a central portion and an adhesive peripheral portion extending from the central portion. In one preferred form, the disc is made of transparent plastic and is gamma radiation resistant. The disc provides a relatively hard surface for a surgeon to apply force to the hemostatic device and thereby to the puncture would, assisting the hemostasis at the puncture wound. The hemostatic pad, preferable a polymer pad, includes hemostatic agent attached thereon.
The hemostatic pad defines an aperture at an approximately central point and an elongated cut extending from the aperture. The aperture is sized to allow passage of the tubular element, for example, catheter, catheter introducer, and etc. The adhesive bandage also defines an associate aperture and elongated cut above the aperture and the elongated cut of the hemostatic pad. The aperture and the elongated cut on the adhesive bandage have a diameter and width being equal to or greater than the diameter and width of the aperture and the elongated cut on the hemostatic pad. The apertures and the elongated cuts allow passage of the tubular element extending from the puncture wound. The aperture and elongated cut on the bandage, which are bigger sized than the aperture and the elongated cut on the hemostatic pad, permit a surgeon to view the bleed site. In one preferred embodiment, the aperture and the elongated cut may form a continuous slit extending from an approximately central point of the device to an edge of the device.
According to one preferred embodiment of the present invention, the elongated cuts on the hemostatic pad and the absorbent pad of the adhesive bandage are along a common bias with respect to the central region of the adhesive backing.
In one preferred form, the adhesive peripheral portion of the bandage is shaped to two adhesive strips. The bandage may further include two peelable covers covering the adhesive side of the two adhesive strips. In another form, the device may only include one peelable cover covering the bottom surface of the whole device.
The disc may further include a rough etched area around a central point of the disc. The rough etched area helps a surgeon to apply force to the hemostatic device, thereby to the puncture wound to assist hemostasis.
The present invention also provides a method for effecting hemostasis at a puncture wound with an adhesive bandage having an opening sized to allow egress of a tubular element disposed in the puncture wound. The adhesive bandage may be applied to or removed from the wound while the tubular element is in the wound. The method includes applying pressure proximal to the puncture wound, and directing the application surface, which contains a hemostatically effective amount of cationic substances, of the adhesive bandage against the puncture wound with sufficient force to prevent fluid from exiting the puncture wound, and permitting the indwelling tubular element going through the adhesive bandage, removing the pressure on the puncture wound, and maintaining the force on the adhesive bandage against the wound for a predetermined time period, removing the force on the adhesive bandage, and remaining the adhesive bandage on the wound site. The adhesive bandage, which is adhered on the wound site, may still remain a slight pressure to the puncture wound, assisting hemostasis of the wound.
According to one aspect of the present invention, the application surface of the pad is a biopolymer of glucosamine, including but not limited to poly-N-acetylglucosamine. In some forms of the invention, the application surface is an acetate salt of a biopolymer of glucosamine.
According to further aspect of the present invention, when a tubular element is disposed in the wound, the predetermined time period is substantially proportional to the diameter of the tubular element.
The present invention provides many benefits, including reducing the time period required to stop bleeding at a puncture wound and decreasing the likelihood that a hematoma will form particularly, but not limited to, cases following removal of an introducer, a catheter or a tube from the puncture wound. These and other features and benefits of the present disclosure will become more apparent upon reading the following specification in combination with the accompanying drawing figures.